1. What is Sending End Current?

Sending End Current is defined as the amount of current injected into a short transmission line from the source or injectors. It represents the current flow at the sending end of the transmission system.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( I_s \) — Sending End Current (Ampere)
• \( P_s \) — Sending End Power (Watt)
• \( V_s \) — Sending End Voltage (Volt)
• \( \Phi_s \) — Sending End Phase Angle (Radian)
• \( \cos \) — Cosine function

Explanation: This formula calculates the sending end current in a three-phase system by dividing the sending end power by the product of 3 times the sending end voltage and the cosine of the phase angle.

3. Importance of Sending End Current Calculation

Details: Accurate calculation of sending end current is crucial for transmission line design, protection system coordination, and ensuring efficient power transfer in electrical transmission systems.

4. Using the Calculator

Tips: Enter sending end power in watts, sending end voltage in volts, and sending end phase angle in radians. All values must be valid (power > 0, voltage > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why is the cosine function used in this formula?
A: The cosine function (cos) represents the power factor, which is the ratio of real power to apparent power in AC circuits.

Q2: What is the significance of the factor 3 in the formula?
A: The factor 3 accounts for the three-phase nature of the power system being analyzed.

Q3: What are typical units for these measurements?
A: Power is measured in watts, voltage in volts, phase angle in radians, and current in amperes.

Q4: When is this calculation particularly important?
A: This calculation is essential for short transmission line analysis, system protection design, and power flow studies.

Q5: Are there limitations to this formula?
A: This formula assumes balanced three-phase conditions and may need adjustment for unbalanced systems or different transmission line configurations.